It's very important to note that the ownership and maintenance of guilds has become very, VERY different since the guild hall update. There are many features unique to guild halls now (material storage and mist wells spring prominently to mind) that are largely unregulated by the game's mechanics; it's up to the guild leaders to figure out how (or even if!) to use them. Where pre-hall update a guild leader might only be in charge of arbitrating disputes and planning special events, a modern guild leader has concrete resources at his or her disposal, which is a much more daunting proposition.

That said, the guild I run (Hydra) has 140 members, with about 16-18 active at any given time; I feel we qualify as a large guild. However, this was not always the case: pre-update, we were much smaller, less than 30. The choice to move from small to large was intentional, and has been enjoyable, but I wouldn't necessarily recommend it for all guilds:

- Small guilds tend to be closer-knit than larger ones, rather like small towns. Members will generally all know (or at least know of) each other. Large guilds, on the other hand, tend to form "pockets" of people who happen to play together or happen to join at the same time. At best, this can help strangers who wouldn't normally have met get to know each other when they run into each other in the field; at worst, it can lead to cliques and isolation within the guild.

- The more people you invite, the more cool folks you meet. Realize, however, that many of the people you invite WILL go inactive, no matter how stringent your interviewing process is. Have a system in place to deal with inactive players , especially if your hall's capacity is small.

- Events for larger guilds need both more and less structure than those for smaller ones. Since there are fewer members, smaller guilds can hold more complex events with a more individual focus, because they don't need to coordinate with as many people; larger guilds, on the other hand, are limited to much simpler events (we like raffles, for instance) that are easy to articulate cleanly to large numbers of people. Of course, larger guilds mean more people participating, so fundraisers and the like tend to be more successful with larger guilds.

- Communal resources can be spread very thin through a large guild, and managing who has the right to use them becomes more difficult with more people. Mist wells in particular are vulnerable to abuse without strong regulation, which means more responsibility for your officers. On the other hand, smaller guild may not have the resources to even HAVE communal resources.

- Larger halls have larger upkeeps. If you want a gleaming edifice of guildly might, make sure your members are willing to pay for it and have a system in place to do so BEFORE you make those additions and waste your money (or, God forbid, go into default).

- You will, as a guild leader, sometimes need to punish people, deny a request, or even kick someone. If you don't want to hurt peoples' feelings, don't be a guildmaster (or a leader in general!), because it's going to happen whatever you do. This becomes truer and truer the larger your organization becomes.

(Impervious' hall is awesome by the way, come visit Hall Hydra sometime!)

Instead of analyzing the pros and cons of owning a guild (which is good), OP can consider these alternatives:

• Guild shopping guide. How to find that guild that is right for you, why Big is not necessarily Better, common marketing flaws to avoid;
• analyze the guild hall update and how it impacts guild's management. This has been roughly mentioned but this update seems to encourage guild to become big (but fail a little short in providing the proper tools for guild management);
• Guild merger. So your GH is in default, your members are starting to leave. Is merger the right thing for me and how would I proceed to do that?
• The mythical active guilds. People seem to have a different notion of guilds being active, and often I found it similar to the mythical legend of Unicorn (everyone heard about it, is talking about it, but few realize they have not seen an inactive guild). Why do people have different notions of "active" and why is it becoming an excuse to throw a fit when a guild is not going the way they want it to be?